GUANTANAMO BAY U.S. NAVAL BASE, Cuba (Reuters) - Far fewer prisoners will be tried in the Guantanamo war crimes tribunals than the Obama administration originally planned because a recent court ruling cast doubts on the viability of some charges, the chief prosecutor for the tribunals said.
The president's Guantanamo Review Task Force had said 36 detainees could be prosecuted, but the tribunal's chief prosecutor put the figure at 20 at most.
The number set by the task force after a review completed in 2010 was "ambitious" in light of a recent court ruling, said Army Brigadier General Mark Martins, the chief prosecutor for the tribunals.
He said captives who would be prosecuted by the Guantanamo tribunals included the seven whose trials are finished and the six facing pre-trial hearings this week and next.
The drastic scaling back of the Guantanamo prosecutions comes after a U.S. appeals court in Washington threw out the conviction of Osama bin Laden's former driver, Salim Hamdan, who was found guilty in 2008 of providing material support for terrorism.
An appeals court agreed with defence arguments that material support was not internationally recognized as a war crime when Hamdan worked for bin Laden's motor pool in Afghanistan between 1996 and 2001.
Congress made material support a war crime in a 2006 law underpinning the Guantanamo tribunals, but the appeals court said the law could not be retroactively applied.
The tribunals were established by the Bush administration and revised by the Obama administration to try suspected al Qaeda operatives and their associates on terrorism charges outside the regular U.S. civilian and military courts.
By the time the appeals court threw out Hamdan's conviction in October 2012, he had finished his sentence and returned to Yemen. But the ruling dissuaded prosecutors from pursuing cases against other prisoners they had considered charging with providing material support to al Qaeda, Martins said.
He spoke to Reuters on Monday as lawyers, court personnel, journalists and observers travelled to the Guantanamo Bay Naval Base in Cuba for two weeks of pre-trial hearings set to begin on Tuesday in the pending cases.
MOST SERIOUS CRIMES
Hours later on Monday, the Pentagon unveiled charges against an Iraqi prisoner identified as a senior al Qaeda commander, Abd al Hadi al Iraqi. Prosecutors allege he funded and oversaw all of al Qaeda's operations against U.S. and allied forces in Afghanistan and Pakistan from March 2002 to 2004.
The charges accuse him of using unlawful tactics such as firing on a medical evacuation helicopter, ordering his forces to kill anyone who tried to surrender, detonating car bombs and suicide vests in civilian areas, and videotaping the resulting deaths for propaganda purposes.
Martins did not identify the handful of other prisoners he still wanted to charge but said he would concentrate on those linked to the most serious crimes.
Pre-trial hearings were set to resume on Tuesday in two of the highest-profile cases at Guantanamo, both of them death penalty cases.
Lawyers will debate a long list of secrecy issues concerning Abd al Rahim al Nashiri, a Saudi captive accused of directing suicide bombers to ram a boat full of explosives into the side of the USS Cole while the warship was fuelling off Yemen in 2000. Seventeen U.S. sailors were killed in the explosion.
Pre-trial hearings are set next week in the case against five prisoners accused of plotting the September 11, 2001, hijacked plane attacks that killed nearly 3,000 people in New York, Washington and Pennsylvania and propelled the United States into an ongoing global war against al Qaeda.
The defendants include the alleged mastermind of the attack, Khalid Sheikh Mohammed, and four men accused of training and providing money to the hijackers.